Association Between Wearable Device Measured Activity and Patient-Reported Outcomes for Heart Failure

Wearable devices are increasingly used in research and clinical care though the relevance of their data in the context of validated outcomes remains unknown. The purpose of this study was to characterize the relationship between smartwatch activity and patient-centered outcomes in patients with heart failure. CHIEF-HF (Canagliflozin: Impact on Health Status, Quality of Life and Functional Status in Heart Failure) was a randomized-controlled clinical trial that enrolled participants with heart failure and a compatible smartphone. Participants were provided a Fitbit Versa 2 and completed serial Kansas City Cardiomyopathy Questionnaires (KCCQs) through a smartphone application. We evaluated the relationship between daily step count and floors climbed and KCCQ total symptom (TS) and physical limitation (PL) scores at baseline and their respective changes between 2 and 12 weeks using linear regression models, with restricted cubic splines for nonlinear associations. In total, 425 patients were included: 44.5% women, 40.9% with reduced ejection fraction. Baseline daily step count increased across categories of KCCQ-TS scores (2,437.6 ± 1,419.5 steps/d for scores 0 to 24 vs 4,870.9 ± 3,171.3 steps/d for scores 75 to 100; P < 0.001) with similar results for KCCQ-PL scores. This relationship remained significant for KCCQ-TS and KCCQ-PL scores after multivariable adjustment. Importantly, changes in daily step count were significantly associated with nonlinear changes in KCCQ-TS (P = 0.004) and KCCQ-PL (P = 0.003) scores. Floors climbed was associated with baseline KCCQ scores alone. Daily step count was nonlinearly associated with health status at baseline and over time in patients with heart failure. These results may inform interpretation of wearable device data in clinical and research contexts. (A Study on Impact of Canagliflozin on Health Status, Quality of Life, and Functional Status in Heart Failure [CHIEF-HF]; NCT04252287)